The present invention relates to a mobile apparatus for turning, and otherwise agitating and aerating, compost materials, in a compost windrow. The apparatus has particular utility in long, relatively massive compost windrows, measuring, e.g., three hundred feet long, sixteen feet wide and eight feet high.
It has become a practice in the composting of biodegradable materials on a mass production basis, to arrange the compost materials in long stacks, or windrows, having humped semi-cylindrical configurations. Periodically, e.g., twice a week, it is necessary to recombine, or stir up the compost materials, in order to quicken, or facilitate, the oxidation and biodegradation process, throughout the windrow. The periodic stirring, or mixing, of the compost materials, redistributes the microbiological agents, and also breaks up the partially decomposed materials into smaller particles, that are then more readily oxidized, and biologically broken down. Another function of the periodic mixing operation, is to aerate the mass of compost materials buried within the interior of the windrow, i.e., beneath the windrow outer surface. Aeration is believed essential to reasonably short biological degradation action.
Conventional apparatus for turning or remixing the compost materials in an elongated windrow, often involves a tunnel-like apparatus that embraces the windrow and moves along the windrow length. A power-driven drum, or rotary rake mechanism, within the tunnel, churns up the compost materials, as the apparatus moves along the length of the windrow. In some cases, the rotary rake merely moves through the compost materials to spread the materials apart.
Another conventional windrow turning apparatus has a powered inclined endless web mechanism on its front end for penetrating the end face of the windrow, as the apparatus moves in a lengthwise direction along the windrow. The endless web has projecting teeth, that exert a shredding action on the compost materials, as the apparatus moves forward into the compost pile, or windrow. In the process, the motion of the web shoots the compost material upwardly, and forwardly, in front of the apparatus.
None of the conventional machines, with which we are familiar, includes the critical aeration mechanisms of the present invention. Aeration is achieved only to a very limited extent, by the churning movement of the compost materials upwardly out of the compost bed. As each particle becomes airborne, it is to a certain extent aerated, at least on its surface.
We believe that there is a clear need for a low cost compost-turning apparatus, that will also produce a greater degree of forced aeration, while at the same time achieving a satisfactory mixing and shredding action. In regard to the cost factor, it is believed that large scale composting could be made more attractive, if machines could be developed that would utilize conventional farm tractors for moving the apparatus and powering the rotary components on the apparatus. One object of the present invention is to provide just such an apparatus, i.e., a compost apparatus that can be towed and operated, in conjunction with a conventional tractor.